1. Field of the Invention
This invention relates to the rocket launching art and more particularly to an improved launch cartridge for launching a rocket powered round from a spike type launcher.
2. Description of the Prior Art
In copending patent applications Ser. No. 364,658 there is described a rocket powered round launched from a spike launcher. As disclosed therein the spike type launcher has a spike that is inserted into the tailpipe of a rocket powered round. A launch cartridge is positioned between the end of the spike and the rocket powered round. The launch cartridge is spaced from the rocket powered round to provide an initial launch volume between the launch cartridge and the rocket powered round in order to control the pressure of the launch gases exerted on the round for launching thereof. That is, as the volume of the initial launch volume is increased, the pressure of the launch gases is decreased and therefore the launch force and launch velocity of the round are decreased. The launch cartridge has a launch charge means which is ignited by the spike launcher and the ignition of the launch charge means generates the hot pressurized launch gases into the initial launch volume.
Additionally, there is diclosed in copending Patent application Ser. No. 364,658 now U.S. Pat. No. 3,886,841 a probe means coupled to the launch cartridge and the probe means extends into the nozzle of the round in order to decrease the nozzle area during the initial launch phase of the round. The decrease in the nozzle area both limits the impingement on the rocket grain of the hot pressurized launch gases and also further decreases the pressure thereof in order to provide a soft light-off of the rocket propellant grain. This achieves two of the desired conditions. The first condition is that the soft light-off prevents rupturing or cracking of the rocket propellant grain, which has been found to occur when comparatively high pressure launch gases are utilized to ignite the grain. The second desired condition is that the rocket propellant grain is not ignited to full thrust until it has safely cleared the launcher thereby protecting the operating personnel from the rocket exhaust. Thus, in the invention of copending patent application Ser. No. 364,658 now U.S. Pat. No. 3,886,841 the launch gases provide both the launch force for launching the round from the spike launcher and igniting the rocket propellant grain. The launch cartridge as described in patent application Ser. No. 364,658 now U.S. Pat No. 3,886,841 is left at the end of the launcher when the rocket powered round is launched therefrom, and covers by its claims the basic structure for the launch cartridge either coupled to the launcher or as a separate item between the end of the spike launcher and the rocket nozzle in the tailpipe of the round.
In copending patent application Ser. No. 561,474 there is defined a detailed structure for providing the coupling of the launch cartridge to the end of the spike launcher and, further, there is described an embodiment thereof in which the probe means is detachable from the remainder of the launch cartridge to provide sealing of the rocket nozzle at the launch thereof in order to prevent ignition of the rocket propellant grain. Prevention of the ignition of the rocket propellant grain thereby provides a pure ballistic trajectory of the round when it is launched from the spike launcher.
The present invention is concerned with the structural modification to a launch cartridge of the type that is insertable into the tailpipe of the rocket powered round as a separate item. As such, it is positionable when the rocket powered round is mounted on the spike launcher between the end of the spike launcher and the rocket powered round and is left at the end of the spike launcher when the round is launched therefrom and in which the probe means is detachably coupled to the launch cartridge to allow either ignition of the rocket propellant grain in the round when it is launched or, alternatively, for sealing the nozzle to prevent ignition of the rocket propellant grain to provide a pure ballistic trajectory of the round when it is launched.